Need Help! PUMA 8-HC troubleshooting flowchart

Results 1 to 3 of 3

Thread: PUMA 8-HC troubleshooting flowchart

  1. #1
    Member
    Join Date
    Oct 2017
    Location
    Canada
    Posts
    23
    Downloads
    0
    Uploads
    0

    Default PUMA 8-HC troubleshooting flowchart

    I'm working on a lathe which has suddenly decided to trip the main breaker instantly on startup when I press "MachineReady" button on panel. None of the internal circit breakers are tripped, however there is a smell in the control cabinet as well as a slight haze inside as well. I have been unsucessful in tracking down the source of the smoke and my documentation on the machine appears incomplete.

    Obviously something very energetic is happening and I am wondering if there is a way to check the spindle motor amp without removing it and pulling it apart, It's my #1 suspect at this point.

    The lathe was working fine on friday, this problem cropped up during startup this morning.
    If anyone has a troubleshooting guide they could look at, maybe post a flowchart, I would be very grateful.

    Serial # P8HC0173, has Fanuc 16-T control.

    Similar Threads:


  2. #2
    Member
    Join Date
    Oct 2017
    Location
    Canada
    Posts
    23
    Downloads
    0
    Uploads
    0

    Default Re: PUMA 8-HC troubleshooting flowchart

    Update: I think I found the problem



    Board doesn't look too badly scored, going to check the IGBTs, and if they're OK, clean the PCB and order a couple of new capacitors.



    Mostly just the solder mask layer vaporized

    Attached Thumbnails Attached Thumbnails PUMA 8-HC troubleshooting flowchart-img-20180312-00690-jpg   PUMA 8-HC troubleshooting flowchart-img-20180312-00689-jpg  


  3. #3
    Member
    Join Date
    Oct 2017
    Location
    Canada
    Posts
    23
    Downloads
    0
    Uploads
    0

    Default Re: PUMA 8-HC troubleshooting flowchart

    Problem solved.

    Input rectifier IGBT pair was toast (the 2 nearest the capacitors). Also a blown 5 amp glass fuse.

    The output IGBT trio was fine.

    The blown 5 amp fuse had me worried as that circuit goes up to the upper control board where all the logic resides so I tried looking for a replacement/rebuilt Amp unit without much luck.
    All that was available was a used ebay unit for $3000 and it looked pretty dirty/ high hours.

    2 IGBT modules and 2 capacitors came to $800 CAD so we decided to risk repairing it ourselves. Cleaned the board, sprayed the damage with conformal coating and replaced the caps and IGBTs.

    On removing the old IGBTs I noticed that the screws that hold them to the heatsink (all 5 IGBTs) were barely finger tight and the heatsink compound was in terrible shape. I suspect these modules have been heat stressed for a long time due to poor mounting pressure which caused the startup failure.

    I don't know if this is a common failure mode but would suggest that if someone has one of these Lathes still running with an original amplifier that it be taken apart and the IGBT's be reseated with good heatsink compound.

    Lathe is back up and running.



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

PUMA 8-HC troubleshooting flowchart

PUMA 8-HC troubleshooting flowchart